Firefox is difficult to sync, it used to be easy.

i have 4 computers and 1 Apple phone that all have Firefox installed. I used to be able to sync all of them with no problem but now it seems it has become extremely difficult and I can't seem to be able to do it as easy any more. My main computer gives me a QR code to scan on my mobile phone but the directions are not clear as to whether I should use my QR reader app or my mobile phone camera. i have not been able to sync my devices because I am having issues signing into my Firefox app on my mobile device. i am just about ready to scrap Firefox on all my devices and start using another browser as it's gotten more difficult to use Firefox. And I would like my old layout for my Windows 11 computer. i do not like the new layout.